What is a Fire Rated Assembly?

Fire rated doors are assemblies that have passed a fire test, whose purpose is to contain fire and smoke in order to allow the safe passage to exit or egress a building during a fire. 

Fire rated assemblies can be constructed of varying materials and have varying ratings for which they were tested.

Fire-rated doors are an integral part of a buildings passive and overall Fire Protection system.

A properly operating Fire Rated Assemblies, like a properly operating fire dampener, is a key component in the compartmentalization of a building in order to help stop the spread of fire, smoke, toxic fumes and other harmful gases.

Fire Rated Assembly and Fire Rated Assembly hardware are susceptible to failure due to constant use, especially in high traffic settings such as hospitals, schools and other crowded corridors. Sustained use can result in the misalignment of the opening, potentially leading to failure and the inability to lock properly. This will deem the opening Non Compliant.

The NFPA claims that heavy use is the most common malfunction of Fire Rated Assemblies, however infrequently used doors, which often go unnoticed, can be subject to ground movement, including earthquakes and building settlement which can lead and contribute to misalignment and jamming.

Annual Fire Rated Assemblies inspections should be seen as necessary maintenance and insurance in case of a fire that these doors function as designed.

Fire Rated Assemblies are rated by the standard time duration they withstand a test fire.

Standard durations are:

  • 20 minutes (1/3 hour)
  • 30 minutes (1/2 hour)
  • ¾ hour (45 minutes)
  • 1 hour (60 minutes)
  • 1 ½ hour (90 minutes)
  • 3 hours (180 minutes)

In order to pass the test, fire rated assemblies must withstand a test fire for the prescribed time period with no flaming on the unexposed surface of the door, remain in the test wall opening, not develop any through opening, meet warpage restrictions at the door edges and limit the flame penetration around the edges of the door.

Fire Rated Assemblies are labeled. These labels must be legible and typically indicate the hour rating, the testing agency, the manufacture, plus other information that may be pertinent and to which that specific door was tested and approved.

In order for a fire rated assemblies to be compliant, the door must have all components listed on the label function in working order